On Trial (1981)

Danny Chan stars as a rich kid, Po, who excels in music. Without the support of his father, who thinks his younger brother Paul (Paul Chung) is doing much better, Po decides to launch his music career alone. On the contrary, Wing (Leslie Cheung) comes from a poor family, but he lies to friends about that. The two boys have been real good friends before Po discovers Wing's family situation, triggering his inferiority complex…